Sunday, May 3, 2009

One thing I keep getting asked why the CBDI Service Architecture and Engineering method distinguishes between the Business Concept Model (describing things as they are in the real world) and the Business Type Model (describing things as they are represented within the enterprise systems).

Here's a simple example. As I mention in my post Will Libraries Survive? there is a conceptual difference between book title and book copy.

"Some libraries identify each physical copy individually, while other libraries merely count the physical copies of a given book title. The physical copies are distinct in the real world, but may be indistinguishable in the library systems. Information strategy includes making this kind of choice."

Let's suppose a library buys ten copies of a book. To start with these copies are physically indistinguishable. The library then attaches some identifying marks to the book, including an ID number. This marking depend on the information strategy - the library could choose to give all ten copies the same number or could choose to give each copy a different number.

If we assume that this id number is used throughout the library systems, then it is clearly important to know whether the id number identifies the book title or the book copy. So this is a critical element of the Business Type Model, which reflects a whole series of strategic decisions of this nature, and then feeds into the identification of core business services.

One important form of business improvement is to increase the differentiation in the Business Type Model. For example, a library that previously didn't distinguish between physical copies could decide to make this distinction in future. But this business improvement doesn't change the underlying reality of books, so the Business Concept Model stays the same.

I shall be writing up some more complex examples for the CBDI Journal and eLearning.

2 comments:

Although the differences between the Concept Model and the Business Type Model does not confuse me -- the fact that the SAE UML Profile does not provide stereotypes for the Concept Model leaves me with some undefined choices as to how to tangibly represent the Concept Model in my UML model and have it stand-out that these are part of the Concept Model. Please include a mapping of the Concept Model to the SAE UML Profile when following up with more details. -- thanks.

When Version 2 of the SAE metamodel was published, we made it clear that we were not attempting to produce a complete metamodel of business modelling concepts and techniques. However, since we produced Version 2 of the SAE metamodel, a lot of useful standards and notations have emerged, especially at the Business Architecture level, so this is certainly an area we'd like to develop further.